Adviser whose comments on Affordable Care Act touched off a furor worked more closely than previously known with White House

Jonathan Gruber, the Massachusetts Institute of Technology economist whose comments about the health-care law touched off a political furor, worked more closely than previously known with the White House and top federal officials to shape the law, previously unreleased emails show.

The emails, provided by the House Oversight Committee to The Wall Street Journal, cover messages Mr. Gruber sent from January 2009 through March 2010....